30 research outputs found
Antibacterial activity of endemic Satureja Khuzistanica Jamzad essential oil against oral pathogens
INTRODUCTION: To assess the antibacterial effects of an Iranian endemic essential oil, Satureja Khuzistanica Jamzad (SKJ) when used as an intracanal antiseptic and interappointment medicament. MATERIALS AND METHODS: Antimicrobial activity and minimum inhibition concentrations (MICs) of SKJ essential oil with and without calcium hydroxide (CH) against eleven aerobic, microaerophilic and anaerobic bacteria were assessed. The evaluation was carried out by agar dilution and well diffusion methods. The results were measured and recorded by an independent observer. Data were analyzed statistically using student t-test. RESULTS: The MIC for eight species was recorded in 0.31 mg/mL of essential oil. Pseudomonas aeruginosa with a MIC value of 1.25 mg/mL appeared to be the most resistant bacterium; while only 0.16 mg/mL of essential oil was sufficient to inhibit the growth of Bacillus subtilis and Staphylococcus aureus. The inhibition zone of the antiseptic oil (at 0.31 mg/mL) with E. faecalis in the well diffusion method was 13 mm; this was comparable with 12.5 mm inhibition zone value of the tetracycline disc (30 ”g). No synergistic effect was found in combination of essential oil and CH powder. CONCLUSION: SKJ essential oil with the concentration of 0.31 mg/mL is effective against most of oral pathogens including E. faecalis
Screening of Streptococcus mutans Sortase A Via Myricetin-Like Inhibitors: In Vitro Evaluation and Molecular Docking-Based Virtual
Background: Dental caries is one of the most common causes threatening human health globally. Sortase A (Srt A) as a transpeptidase, mediates the attachment of the Streptococcus mutans cell wall to dental
surfaces by biofilm formation. Due to the development of multidrug-resistance bacteria, attempting to discover growth inhibitors is logical and promising.
Objectives: The current study aimed at the experimental and docking-based virtual screening of myricetin-like inhibitors for the inhibition of Srt A enzyme in S. mutans isolates.
Methods: Sixty-three S. mutans were isolated from pupils based on cultural, morphological, and biochemical characteristics (N = 150). After identifying the srtA gene using the polymerase chain reaction (PCR) with specific primers, a broth microdilution test was conducted according to CLSI-2020 criteria to determine the minimum inhibitory concentration (MIC) of myricetin. The in silico exploration of Srt A inhibitors was performed using AutoDock 4.2.6.
Results: The frequency of S. mutans isolates containing the srtA gene was 87.3% of which, fifty isolates (79.4%) were categorized as susceptible to myricetin (MIC †16 Όg/mL). Of 20 ligands having a high degree of similarity with myricetin, the best docking results were related to ligand 2.
Conclusion: It was concluded that myricetin has an inhibitory effect on oral bacteria in vitro, and ligand 2 had the most negative binding energy (-4.66 kcal/mol) and favorably interacts with the key amino acid residues at the active site of Srt A. Accordingly, this ligand can be utilized as a lead compound for further studies to discover novel inhibitors targeting Srt A in S. mutans
The Study of Economic, Financial, and Political Risks on the Resource Curse Vulnerability Index in the Countries of the Mena Region
Today, many risks, including economic, financial, and political ones, threaten the economies of countries. On the other hand, governments try to manage the negative consequences and neutralize or minimize their impact on the economy. A review of the situation shows that most underdeveloped and developing countries, especially those rich in natural resources (resource rents), have been severely affected by these internal and external shocks (resource curse) due to their high dependence on oil revenues; in contrast, developed countries have suffered less by adopting appropriate policies. The purpose of this study is to construct and introduce a composite resource curse vulnerability index and then investigate the impact of each of the economic, financial, and political risks on the resource curse vulnerability index. Therefore, using the latest available data, the econometric approach of panel data was performed for 14 selected countries in the Mena region from 2005 to 2018. Results indicate an inverse and significant relationship between independent variable risks on the dependent variable (resource curse vulnerability index), which confirms the research hypotheses
Examining Drinking Water Security in Rural Areas of Iran: Perspectives from a Quantitative Analysis
Water is one of the basic needs of individuals and communities. In a way, without it, the growth and sustainability of societies is not possible. In recent decades, due to the effects of climate change and human activities, many parts of the world have faced water-related crises. Hence, this issue has jeopardized the sustainability of villages, especially in developing countries. Therefore, the purpose of this study is to quantify drinking water security in rural areas of Iran during the years 2013-2019. For this purpose, this paper has developed a rural water security assessment framework with four dimensions and ten indicators. The scale of the rural water security index is between 1 and 5. Based on findings, three dimensions: âavailabilityâ, âaccessibilityâ and âwater health and sanitationâ, all show an upward trend, reflecting an overall improvement of water-related infrastructure in rural areas. Whereas the âeconomic value of waterâ dimension depicts a steady trend. Also, for the period of 2013-2019, the results show the improvement of rural drinking water security in Iran
Reversibility Test of Oil Demand Function of OECD Countries Importing Oil from Iran with an Emphasis on Technological and Environmental Considerations: Symmetric and Asymmetric Models
The study aimed to estimate the oil demand function of the OECD countries importing oil from Iran based on symmetric and asymmetric specification. To estimate symmetric and asymmetric patterns in this study, data from 1970 to 2014 for OECD countries importing oil from Iran including France, Germany, Greece, Italy, Japan, Poland, Spain, Turkey, England, South Korea, Czech, Netherlands and Belgium were used. The results of the panel root test showed the first-order difference reliability of the variables and the co-integration test confirmed a long-term relationship between the variables. Therefore, the models were estimated using the fully modified ordinary least square method (FMOLS). The results of the model estimation indicated the irreversibility of the oil demand function of the OECD countries importing oil from Iran.
Keywords:Â Oil demand function reversibility, OECD countries, modified ordinary least square method, panel co-integration test
JEL Classifications:Â D43, E31, L7
Climate trends and extremes in the Indus River Basin, Pakistan: implications for agricultural production
ABSTRACT: Historical and future projected changes in climatic patterns over the largest irrigated basin in the world, the Indus River Basin (IRB), threaten agricultural production and food security in Pakistan, in particular for vulnerable farming communities. To build a more detailed understanding of the impacts of climate change on agricultures in the IRB, the present study analyzes (1) observed trends in average temperature, precipitation and related extreme indicators, as well as seasonal shifts over a recent historical period (1997-2016); and (2) statistically downscaled future projections (up to 2100) from a set of climate models in conjunction with crop-specific information for the four main crops of the IRB: wheat, cotton, rice and sugarcane. Key findings show an increasing trend of about over 0.1ÂșC/year in observed minimum temperature across the study area over the historical period, but no significant trend in maximum temperature. Historical precipitation shows a positive annual increase driven mainly by changes in August and September. Future projections highlight continued warming resulting in critical heat thresholds for the four crops analyzed being increasingly exceeded into the future, in particular in the Kharif season. Concurrently, inter-annual rainfall variability is projected to increase up to 10-20% by the end of the 21st century, augmenting uncertainty of water availability in the basin. These findings provide insight into the nature of recent climatic shifts in the IRB and emphasize the importance of using climate impact assessments to develop targeted investments and efficient adaptation measures to ensure resilience of agriculture in Pakistan into the futur
Evaluation of Repellency Effect of Essential Oils of Satureja khuzestanica (Carvacrol), Myrtus communis (Myrtle), Lavendula officinalis and Salvia sclarea using Standard WHO Repellency Tests.
Background: Using special lotions and repellent sprays on skin is one of the effective methods to prevent Arthropods biting which was verified in this study.
Methods: Essential oils of four plants (Satureja khuzestanica, Salvia sclarea, Lavendula officinalis and Myrtus communis) were separately extracted by Clevenger used hydro distillation method. Then separated solutions with 10%, 20% and 40% concentrations of essential oils of plants in 99.6 % ethanol were prepared. WHO guidelines for efficacy testing of mosquito repellents for human skin were used on different concentrations of essential oils of plants, traditional repellents (DEET, 50% and 33%) as positive control, and ethanol 99.6% and naked hands as nega- tive controls.
Results: In negative control groups, the number of bits were comparable (P= 0.42) and had decreasing time trends (naked hands P= 0.011, ethanol P< 0.001). In all time points, minimum bites were observed in traditional repellents and it was significantly less than the other groups (P< 0.001). The time trend in the number of bites in the other groups was positive and showed minimum number of bites in time zero in all groups. We also found that the con- centration of repellents had association with the number of bites. The maximum and minimum numbers of bites were observed with 10% and 40% concentrations respectively in all groups.
Conclusion: Essential oils of Salvia sclarea, Lavendula officinalis and Myrtus communis have repellency effect,even with 10% concentration of essential oils
Evaluating Elasticity of Income and Price on Water Demand Using PollakâWales Method
Iran is located in an arid and semi-arid region and will be joining the âThirsty Statesâ by 2025. However, water use efficiency and water services seem to be low and inadequate, as they do not match the emerging conditions of water scarcity. As part of the research efforts required to address the problems in this area, this paper endeavors to use a simple, efficient, precise, and practical method for determining the income and price elasticity of the domestic drinking water demand. The household income in this method is replaced by a good, measurable substitute index which is the household land and building areas. Log-log functions are presented for different blocks for the statistical period 2001-2004. Correlation coefficients obtained were above 40% in all the functions. The average income elasticity ranged from 0.704 to 0.411 for the first to the fifth blocks, respectively. This shows that water is a necessary and non-substitutable commodity in the household portfolio. The price demand elasticity was estimated using the modified PollakâWales method, price variations over two different time periods, and income elasticity over the statistical period. The price elasticity value varied from -0.3 to -0.01 for the second to fourth blocks, respectively. This indicates the inelasticity or low elasticity of water for current prices
Comparison of ultrastructure and morphology of mouse ovarian follicles after conventional and direct cover vitrification using different concentrations of ethylene glycol
Background: Many attempts have done to improve cryopreservation of
mammalian ovaries using simple, economical and efficient technique
âvitrificationâ. Objective: The aim of the present study
was to compare the mouse ovaries cryopreservation by direct cover
vitrification (DCV) using different concentrations of ethylene glycol
(EG) with conventional vitrification methods (CV). Materials and
Methods: Ninety NMRI mice were sacrificed by cervical dislocation;
their ovaries were divided into three main experimental groups: control
or non-vitrified group, CV group and DCV groups with 4, 6 and 8M EG as
cryoprotectant. After vitrification-warming, the viability of
mechanically isolated follicles and the morphology of ovarian follicles
by light and electron microscopes were studied. Results: The
normality of primary and preantral follicles in non-vitrified and CV
groups were higher than those achieved by DCV groups (p<0.001). The
survival rates of isolated follicles in non-vitrified, CV and DCV
groups with 4M, 6M and 8M ethylene glycol were 98.32, 96.26, 84.10,
85.46 and 84.56 %, respectively and in DCV groups it was lower than
other groups (p<0.001). The ultrastructure of ovarian follicles was
well preserved in CV technique. The follicles in DCV groups appeared to
have vacuolated oocyte with nuclear shrinkage and irregular
distribution of cytoplasmic organelles. Their mitochondria were located
mainly in the sub cortical part of the oocyte and the granulosa cells
demonstrated some signs of degeneration. Conclusion: DCV of mouse
ovarian tissue using only EG has induced some alteration on the fine
structure of follicles. The integrity of mouse ovarian tissue was
affected by DCV technique more than CV